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bb57

How long have you owned this pair?  Do you know what brand caps are currently in place?  If they are Sprague compulytics there should be no rush to change, otherwise in what area of the country you are you located? You may be near someone who is willing to help. Do you have photos?

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I restored the crossover in my 10Pi and they sound wonderful.

I did them with the crossovers in place. Some solder points were difficult due to all the wiring but I never scorched a wire sleeve.

I'm in the metrowest area of MAsshole

 

131_3129.JPG

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The 10pi never had Sprague capacitors.

bb57...where are you located?

Roy

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3 hours ago, DavidR said:

I thought some of the early versions had Sprague but not the MkII.

Interesting...I guess I've only been seeing the later ones. You obviously have a photo of one with Spragues. Is that one yours?

Roy

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2 minutes ago, RoyC said:

Interesting...I guess I've only been seeing the later ones. You obviously have a photo of one with Spragues. Is that one yours?

Roy

No, I have a Mk2. I googled AR10Pi and went to images. I found several with Sprague caps.

Here's a pic before the recap >

 

10pi_xo3.JPG

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1 hour ago, DavidR said:

No, I have a Mk2. I googled AR10Pi and went to images.

The manufacture date code on the large Sprague shows 17th week of 1973, and I assume the "75" stamped in the cabinet could mean 1975, so that one is certainly a very early specimen. It makes sense, as I have seen more than a few of the more common AR-11 sibling with at least one Sprague capacitor.  At any rate, good catch David...and apologies to Aadams who makes a valid point.

Roy

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On 6/16/2020 at 5:08 AM, bb57@comcast.net said:

I live in Cape Coral FL, Thanks

Do we have any members down there that could help bb57 ?

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Hi People , I just picked the speakers up AR 10Pi i would like to recap these with new ones like original if possible, I THINK i can replace them if i knew where to get new ones if they can be just swapped out & i new which ones are the caps , Need help on the ones to replace & where to get them, I have been looking for a crossover schematic but the one i found show only 3 capacitors 2500 uf , 20uf ,100,uf, Any help would be greatly appreciated,I live SW Fl thanks < LLoyd

63BB188C-0E99-4958-8F0A-E6C0BED95A21.heic 351489E9-D0EC-4731-A0F5-F39A4900AD4D.heic 082621AE-BE05-4661-9A5B-0120A9CA2FD1.heic 67BFB37E-877A-4F36-8B0C-AE83F20D5BFD.heic

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The 3 PVC black with red ends and the 2 metal can capacitors. 10uF, 20uF, 40uF, 100uF and 2500uF. The 2500 has a resistor across it that you should replace with a Mills brand.

For the 2500uF you will need to solder 2x1000 + 1x500uF together in parallel.

Madisound or Parts Connextion will have caps.

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Lioyd

A belated welcome. Nice speakers!

Regarding pictures, we love 'em but your iPhone pics are in a proprietary format, HEIC, which does not show up in the post so they have to be downloaded individually. And they're too big. If you have any kind of editing program, convert them to jpeg and make them about 100KB. I use Photoshop elements, resize to about 6" on the long side with a resolution of about 100 then save with a quality level of 8.

DavidR's advice and his pic in the third post are good but it sounds like you wanted more guidance. (disclaimer: I have never worked on a 10pi).

For the smaller caps (10, 20, maybe 40) you may want to use film caps.  Film caps last virtually forever and are inexpensive for lower values. Look at this page on Parts Express https://www.parts-express.com/cat/metalized-polypropylene-crossover-capacitors/294  10uF is about $5.50, 20uF about $7.25, 40uF about $12, 100uF $26. If you try erseaudio.com they have lower prices https://www.erseaudio.com/Products/PEx250v 10uF is under $2, 20 is under $4, 39uF (close enough) is $4.35.

From the photo it looks like DavidR used ALL electrolytic caps, and that is certainly a valid approach (preferred by some). Those lower value caps may be Mundorf E-caps which are supposed to be very nice. https://www.partsconnexion.com/MUNDORF-71870.html

These are the Mills resistors https://www.parts-express.com/cat/crossover-resistors/300?N=19849+4294967118+4294963624&Ne=10166&Nrs=collection()%2Frecord[endeca%3Amatches(.%2C"P_PortalID"%2C"1")+and+endeca%3Amatches(.%2C"P_Searchable"%2C"1")]&PortalID=1

Parts Express does not have 1000uF NPE caps nor does Madisound or Parts Connexion. I did find these Bennics (what David used) at Meniscus  https://meniscusaudio.com/product/npe-1000uf/ 

btw, you don't have to use Mills resistors. If you are ordering from Parts Express anyway, add them in. Looking at the schematic, the resistor on the 2500uF is 10 ohms/10 watts. There is also a 15 ohm/10w resistor in the crossover. If you order from Meniscus (for the 1000uF Bennics) they have a lot of quality resistors. The 10 ohm MOX is a good, economical choice. I've never used Twisted Zister but have used similar resistors from Ohmite. The short lead ones for $1.65 are a bargain (and there is no problem with the higher wattage--just don't go lower than 10w). Or you can go with Mundorf but at $7.10 each they seem overly pricey to me. Or to go really cheap, add standard wirewound resistors to your Erse order. They're $0.26 each.

Good luck with those nice speakers and keep us posted.

Kent

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wow lots of info, are the cap all 250V , and I can Put 2,-1000 uf and-1-500uf Bennics together to make the 2500 uf cap? , Well this does'nt look to hard, LOL Thank you guys, I Guess there is no place that sells those 100uf & 2500uf in the aluminum cans that would be much easier. Thanks again, Lloyd

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The caps should be 100VDC or higher. Yes, you cn put capacitors in parallel to reach the desired value. The values are additive, so 1000 + 1000 + 500 = 2,500.

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Great that helps, the resistors that are there ,any good or replace also? thanks again for the help ,without it would not even try this, I have no testing equipment, if I am just replacing the caps do I need any test equipment, tnaks , Lloyd

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2 hours ago, DavidR said:

Usually they are still good and very close to stated value. However, the Mills are quieter. The 15 ohm was not easy to get to and solder.

So, IMHO, maybe you'll want to skip the 15 ohm. Really depends on how confident you are about reaching in there and soldering. If an experienced restorer like David says it's not easy, may not be worth the effort.

I would definitely replace the 10 ohm. You'll be making a bundle, as shown in David's picture: 2 x 1000uF, 1 x 500uF and 1 x 10 ohm resistor. It's nice to use a new resistor with fresh, long leads. In this case I would not use the Twisted Zister I mentioned previously. Stick with Mills, MOX or standard sand-cast. You may want to check the length of the 1000uF cap and compare to the length of those resistors. The Mills fits nicely. You don't want a resistor that's a lot longer than the caps (just for ease of soldering).

Don't be put off by the prospect of soldering those NPE caps in parallel. It's not difficult and  in some ways it's really easier than the big silver can because you have more room to work.

Kent

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22 hours ago, JKent said:

Lioyd

A belated welcome. Nice speakers! ......................................................

Parts Express does not have 1000uF NPE caps nor does Madisound or Parts Connexion. I did find these Bennics (what David used) at Meniscus  https://meniscusaudio.com/product/npe-1000uf/ 

......................................................................

Kent

Yes, Madisound does carry a 1000uF electrolytic >>>     https://www.madisoundspeakerstore.com/m.d.l.-electrolytic-capacitor-100vdc/mdl-1000-mfd-non-polar-electrolytic-capacitor-100v/

Meniscus is a crap shoot with what you will get for an electrolytic brand. The picture they use does not always equate to what you get. Sometimes they send a Black Beauty; the same brand Parts Express sells and you will pay a lot more to Meniscus.

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Oh. Thanks. I was looking at Bennics at Madisound and missed that. So Madisound has all the NPEs: 1000, 5000, 100 and 40. Lloyd will need to use a film cap for the 10uF https://www.madisoundspeakerstore.com/m.d.l.-xpp-poly-capacitor-250vdc/mdl-xpp-polypropylene-10mfd-250v/ and I think THAT will be a tight fit given the placement of the original. 

Lloyd; Madisound is a good company to deal with. Deliveries are usually fast and shipping is reasonable. If you get all your caps from them you can also get the 10 ohm resistors. Mundorf MOX is $2 ans at 52mm the same length as the 1000uF cap. You could use the Mundorf copper/nickle but they are $7 and out of stock. They are also out of the plain wirewound 10 ohm 10 watt but you could use the 10 ohm 15 watt. Personally I'd go with the green Mundorf if only ordering from Mad.

Kent

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A little hint that may help soldering in new parts. The 10Pi crossover has lots of wires in the middle of the cabinet and the attach point is at the base of those wires. So if you recap with the boards in place like I prefer to do I found that when I snipped the leads of the old caps I ALWAYS left as much of the old lead as possible and attached the new cap lead to that old lead.

I chose to go all electrolytic because I wanted them to be as designed with NPE caps. However, I did put a small polypropylene film cap (Vishay 1837 0.01uF ) in parallel with each series cap. I liked the results so much I did my AR90s the same way. But I only did the series caps this way.

 

130_3080 - Copy.JPG

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9 hours ago, DavidR said:

However, I did put a small polypropylene film cap (Vishay 1837 0.01uF ) in parallel with each series cap. I liked the results so much I did my AR90s the same way.

I attempted to use those same Vishay 1837 bypass caps on a recap project but found the leads to be way to short. I wound up using the Parts Express Film and Foil bypass caps which have longer leads. I ordered some 20 AWG tinned copper wire from Remington Industries and  plan on using it to extend the Vishay leads on my next recap project.

rTyZBHm.jpg

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